Railway vehicles, particularly those used for public transportation, often include a superstructure for carrying passengers. The superstructure rides on a bogey, also sometimes referred to as a truck, which includes at least one wheel axle, more typically two, for traveling along the rails. Generally, a primary suspension system is positioned between the wheel axles and the bogey and a secondary suspension system is positioned between the bogey and superstructure.
Superstructures have at least one access, e.g. a door, to allow passengers or cargo to enter or exit the superstructure when the railway vehicle reaches a loading platform. Because load may vary, the superstructure may sometimes need to lift or lower a variable distance to allow the floor of its access to reach the approximate level of the platform.
For a variety of reasons, applicants are dissatisfied with existing solutions for lifting and lowering superstructures.